package com.thti.mecool.client.widget;

import java.util.Date;

import android.R;
import android.content.Context;
import android.util.AttributeSet;
import android.view.Gravity;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.BaseAdapter;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.ProgressBar;
import android.widget.TextView;

public class MyListView extends ListView implements OnScrollListener {
	public MyListView(Context context) {
		super(context);
		init(context);
	}

	public MyListView(Context context, AttributeSet attrs) {
		super(context, attrs);
		init(context);
	}

	public MyListView(Context context, AttributeSet attrs, int defStyle) {
		super(context, attrs, defStyle);
	}

	private final static int RELEASE_To_REFRESH = 0;
	private final static int PULL_To_REFRESH = 1;
	private final static int REFRESHING = 2;
	private final static int DONE = 3;
	private final static int LOADING = 4;
	private final static int RATIO = 3;
	private TextView tipsTextview;
	private TextView lastUpdatedTextView;
	private ProgressBar progressBar;
	private boolean isRecored;
	private int footContentHeight;

	private int startY;
	private int lastItemIndex;

	private LinearLayout footview;
	
	private int count;
	private int state;

	private boolean isBack;

	private OnRefreshListener refreshListener;

	private boolean isRefreshable;


	private void init(Context context) {
		setCacheColorHint(context.getResources().getColor(R.color.transparent));
		footview=new LinearLayout(context);
		footview.setOrientation(0);
		footview.setGravity(Gravity.CENTER);
		LinearLayout textLayout=new LinearLayout(context);
		textLayout.setOrientation(1);
		progressBar=new ProgressBar(context);
		footview.addView(progressBar);
		footview.addView(textLayout);
		tipsTextview = new TextView(context);
		tipsTextview.setGravity(Gravity.CENTER);
		tipsTextview.setTextSize(24);
		lastUpdatedTextView = new TextView(context);
		lastUpdatedTextView.setGravity(Gravity.CENTER);
		textLayout.addView(tipsTextview);
		textLayout.addView(lastUpdatedTextView);
		measureView(footview);
		footContentHeight = footview.getMeasuredHeight();
		footview.getMeasuredWidth();

		footview.setPadding(0, -1 * footContentHeight, 0, 0);
		footview.invalidate();

		addFooterView(footview, null, false);
		setOnScrollListener(this);
		state = DONE;
		isRefreshable = false;
	}

	@Override
	public void onScroll(AbsListView arg0, int firstVisiableItem, int arg2,
			int arg3) {
		count=arg3;
		lastItemIndex=firstVisiableItem+arg2;
	}

	@Override
	public void onScrollStateChanged(AbsListView arg0, int arg1) {
	}

	@Override
	public boolean onTouchEvent(MotionEvent event) {

		if (isRefreshable) {
			switch (event.getAction()) {
			case MotionEvent.ACTION_DOWN:
				if (lastItemIndex == count && !isRecored) {
					isRecored = true;
					startY = (int) event.getY();
				}


			case MotionEvent.ACTION_UP:

				if (state != REFRESHING && state != LOADING) {
					if (state == DONE) {
						// 什么都不做
					}
					if (state == PULL_To_REFRESH) {
						state = DONE;
						changeHeaderViewByState();

					}
					if (state == RELEASE_To_REFRESH) {
						state = REFRESHING;
						changeHeaderViewByState();
						onRefresh();

					}
				}

				isRecored = false;
				isBack = false;

				break;

			case MotionEvent.ACTION_MOVE:
				int tempY = (int) event.getY();

				if (!isRecored && lastItemIndex == count) {
					isRecored = true;
					startY = tempY;
				}

				if (state != REFRESHING && isRecored && state != LOADING) {

					// 保证在设置padding的过程中，当前的位置一直是在head，否则如果当列表超出屏幕的话，当在上推的时候，列表会同时进行滚动

					// 可以松手去刷新了
					if (state == RELEASE_To_REFRESH) {

						setSelection(count);

						// 往上推了，推到了屏幕足够掩盖head的程度，但是还没有推到全部掩盖的地步
						if (((startY - tempY) / RATIO < footContentHeight)
								&& (startY - tempY) > 0) {
							state = PULL_To_REFRESH;
							changeHeaderViewByState();
						}
						// 一下子推到顶了
						else if (startY - tempY <= 0) {
							state = DONE;
							changeHeaderViewByState();
						}
						// 往下拉了，或者还没有上推到屏幕顶部掩盖head的地步
						else {
							// 不用进行特别的操作，只用更新paddingTop的值就行了
						}
					}
					// 还没有到达显示松开刷新的时候,DONE或者是PULL_To_REFRESH状态
					if (state == PULL_To_REFRESH) {

						setSelection(count);

						// 下拉到可以进入RELEASE_TO_REFRESH的状态
						if ((startY - tempY) / RATIO >= footContentHeight) {
							state = RELEASE_To_REFRESH;
							isBack = true;
							changeHeaderViewByState();
						}
						// 上推到顶了
						else if (startY- tempY  <= 0) {
							state = DONE;
							changeHeaderViewByState();
						}
					}

					// done状态下
					if (state == DONE) {
						if (startY - tempY > 0) {
							state = PULL_To_REFRESH;
							changeHeaderViewByState();
						}
					}

					// 更新headView的size
					if (state == PULL_To_REFRESH) {
						footview.setPadding(0, -1 * footContentHeight
								+ (startY - tempY) / RATIO, 0, 0);

					}

					// 更新headView的paddingTop
					if (state == RELEASE_To_REFRESH) {
						footview.setPadding(0, (startY - tempY) / RATIO
								- footContentHeight, 0, 0);
					}

				}

				break;
			}
		}

		return super.onTouchEvent(event);
	}

	// 当状态改变时候，调用该方法，以更新界面
	private void changeHeaderViewByState() {
		switch (state) {
		case RELEASE_To_REFRESH:
			tipsTextview.setVisibility(View.VISIBLE);
			lastUpdatedTextView.setVisibility(View.VISIBLE);
			tipsTextview.setText("松开刷新");
			break;
		case PULL_To_REFRESH:
			tipsTextview.setVisibility(View.VISIBLE);
			lastUpdatedTextView.setVisibility(View.VISIBLE);
			// 是由RELEASE_To_REFRESH状态转变来的
			if (isBack) {
				isBack = false;

				tipsTextview.setText("下拉刷新");
			} else {
				tipsTextview.setText("下拉刷新");
			}
			break;

		case REFRESHING:
			footview.setPadding(0, 0, 0, 0);
			tipsTextview.setText("正在刷新...");
			lastUpdatedTextView.setVisibility(View.VISIBLE);
			break;
		case DONE:
			footview.setPadding(0, -1 * footContentHeight, 0, 0);
			tipsTextview.setText("下拉刷新");
			lastUpdatedTextView.setVisibility(View.VISIBLE);
			break;
		}
	}

	public void setonRefreshListener(OnRefreshListener refreshListener) {
		this.refreshListener = refreshListener;
		isRefreshable = true;
	}

	public interface OnRefreshListener {
		public void onRefresh();
	}

	public void onRefreshComplete() {
		state = DONE;
		lastUpdatedTextView.setText("最近更新:" + new Date().toLocaleString());
		changeHeaderViewByState();
	}

	private void onRefresh() {
		if (refreshListener != null) {
			refreshListener.onRefresh();
		}
	}

	private void measureView(View child) {
		ViewGroup.LayoutParams p = child.getLayoutParams();
		if (p == null) {
			p = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.FILL_PARENT,
					ViewGroup.LayoutParams.WRAP_CONTENT);
		}
		int childWidthSpec = ViewGroup.getChildMeasureSpec(0, 0 , p.width);
		int lpHeight = p.height;
		int childHeightSpec;
		if (lpHeight > 0) {
			childHeightSpec = MeasureSpec.makeMeasureSpec(lpHeight,
					MeasureSpec.EXACTLY);
		} else {
			childHeightSpec = MeasureSpec.makeMeasureSpec(0,
					MeasureSpec.UNSPECIFIED);
		}
		child.measure(childWidthSpec, childHeightSpec);
	}

	public void setAdapter(BaseAdapter adapter) {
		lastUpdatedTextView.setText("最近更新:" + new Date().toLocaleString());
		super.setAdapter(adapter);
	}
}
